Disk Utility won't let me resize a partition

Hi

i'm having the same problem.

My previously deleted partition can't be read. and the other partition can't be enlarged.

I'm not sure how to write the terminal command to get my full hard disk back.

Kindly help

You should be able to click on the partition you want to resize, (e.g., 3TB) and stretch it to fill the blank space just beyond it. Different versions of Disk Utility may have required you to type the new size in the text box instead, but the key concept was selecting the partition you wanted to change.

You cannot eliminate a partition with data in it (e.g., Merrell) by using the Partition tab. You would have to back up to the display that shows the drives by Physical device, and work from there. You may need to use Erase.

Oh, you I see form your screenshot you have a Logical Volume Group. That's the Problem. Not trivial to fix.

There was a Bug introduced in 10.8.4 and carried forward into current versions. Using ERASE function on an Internal drive over 2.2TB created a Logical Volume Group, perhaps in contemplation of new features yet to come, or a Fusion Drive setup.

To Fix, you can ERASE in an External Enclosure, or use a version of Disk Utility that pre-dates 10.8.4 (the 10.6 DVD comes immediately to mind) to ERASE that drive again, and it will NOT create a Logical Volume group.

There is also a way this can be done using Terminal commands. It requires two windows open in Terminal, and the commands are not trivial, but I could look them up if you need to use that method.

SnipperJS did the research and posted the solution on this thread:

Re: Disk Utility defaulted to Logical Volume Group format for new 4TB HDD and won't let me change to GUID. Is that a pro…

The essence is:

First run diskutil cs list to get the UDID of the volume group and the logical volume. Then you just delete the volume and the group that was created when Diskutil did the bad 'erase' -- when you do that, your drive will be left with a single large partition and you just don't use Erase after that - use Partition in Diskutil [or go back to Disk Utility] and you'll be all set.

The commands are:

diskutil cs list

diskutil cs deleteVolume <Logical Volume UDID>

diskutil cs delete <logical volume group UDID>

BE WARNED - if you have a fusion drive, this will also show up as a Logical Volume Group and you need to make sure you're picking the right ones or you'll have serious data loss. The command line is unforgiving.

You will need two Terminal windows open to cut-and-paste the huge UDID strings -- one for the Logical Volume, and one for the Logical Volume Group.

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